Smoking in pregnancy is associated with a variety of complications, including low birth weight (LBW), intrauterine growth restriction (IUGR), antenatal bleeding and pre-term birth (PTB). These significant health hazards could largely be prevented with successful antepartum smoking cessation. In recognizing both the success and the limitations of counseling based smoking cessation programs, we are interested in piloting the use of pharmacologic agents for reduced smoking during pregnancy. The first objective of the proposed research is to evaluate the efficacy of a pharmacologic aid for successful smoking cessation in pregnancy. The specific aims include evaluating bupropion SR's efficacy for both cessation and reduction of antenatal smoking by comparing pregnant women receiving smoking cessation counseling combined with placebo to those pregnant women who receive smoking cessation counseling combined with bupropion SR. The second objective of the proposed research is to evaluate the safety of bupropion SR used for smoking cessation in pregnancy. The specific aims include determining the adverse events and adverse effects associated with antenatal bupropion administration. Secondarily, the pilot seeks to evaluate the impact of bupropion SR on maternal well being, anxiety, depression, psychosocial variables and neonatal outcome (birth weight, Apgar scores, and neonatal intensive care unit admission rate). This research will consist of a pilot double blind placebo controlled randomized trial in which pregnant women who self-report continued smoking at the inception of prenatal care, will be randomized to one of two groups. The interventions will consist of brief smoking cessation counseling in combination with either placebo or bupropion SR. Participants will be surveyed to determine important demographic factors, psychosocial variables, and intercurrent medical illnesses, including measures of psychiatric disease, particularly concurrent depression. Maternal outcome measures will include cessation and smoking reduction rates by self-report and biochemical analysis (urinary cotinine and breath carbon monoxide analysis). The proposed research seeks to evaluate whether a pharmacologic aid (bupropion SR) administered antenatally can achieve higher rates of smoking cessation and smoking reduction without imposing serious adverse outcome.